Finned Channel Strip Heaters for Precise 3D Printer Application

3D Printing

Tempco was approached by a customer in the 3D Printing industry who was seeking a basic, finned channel strip heater (CSF). The design specifications that they gave to Tempco included:

a flexible lead wire termination
a ground wire
a size constraint on the fins
a length constraint on the overall heater length
a specific lead wire gauge

After a few exchanges regarding design specifications, Tempco designed a heater with a smaller, more appropriate lead wire gauge and the customer approved Tempco’s heater design.

A few months later the customer contacted Tempco to discuss alternate design ideas. After the original heater was installed, they discovered that typical strip heater uniformity issues were a problem within their application. Any standard channel strip heater (from any manufacturer) will have cold sections at each end because of the layout of the internal coils. Our customer shared thermal photos of their application and the heater installation with us, along with two potential solutions to the problem that they had found. One solution was to create multiple heating zones, also known as distributed wattage, within the heater. Another solution was to extend the heated length while maintaining the same number of fins and the overall length. The second solution would push the cold sections farther away from the heating fins, making the ends a bit hotter. Tempco implemented the second idea and developed a second finned strip heater design for them.

While the new heater design worked better than the original when installed in their application, Tempco’s customer decided that they still wanted to explore a strip heater design with the Distributed Wattage (Type DW) power variation. After viewing updated thermal pictures that the customer provided, we recommended increasing the watts by 30% at the lead end and 20% at the opposite end. The adjustment would only need to be made to 2” on both ends of the heated length.

As the third heater design was going through our Production Department, the customer inquired about a new design/layout with a different power variation. They wanted two heaters with similar dimensions, but completely different internal layouts, that worked together. The first heater would only have 4” heated sections on both ends and a large cold section in the middle [Figure 1]. The second heater would have a full heated length, but independent heating elements the long way [Figure 2]. Both heaters were excellent candidates for Tempco’s Dual Circuit (Type DWV) configuration, allowing our customer to control the heat zones independently and achieve an optimal heating pattern.

The final designs had a Flexible Lead Wire (Type L1) electrical termination on both sides, plus a Type GL ground lead power variation on one side. To make them somewhat more distinguishable and reliable than wire markers, each circuit had its own color lead wire: red or black. The heater with the large cold section in the middle had the same color lead wires on the ends [Figure 1]. The heater with dual circuits running the length of the heater had leads on just one end - a red/black/green wire combination on one side and red/black on the opposite side [Figure 2]. After testing the set, a few simple changes were made:

Increase in watts on both heaters
tighten up the tolerance on the ohms and overall lengths
change the lengths of the lead wires on one side to account for having to go across the application

Figure 1 and Figure 2

Finned Channel Strip Heater

Both designs required multiple iterations to reach the uniform temperature that our customer was seeking. A few sample orders to gauge the impact of the modifications greatly helped get the customer to where they needed to be. It can be difficult to reach the level of precise heating that our customer needed on a first attempt for a new custom design, but the process went smoothly with Tempco involved!